1. Field of the Invention
The present invention relates to an oil artificial lift unit for oil production and more particularly, to an oil artificial lift unit that uses an electrical submersible pump driven by a circular linear synchronous three-phase motor with rare earth permanent magnet.
2. Description of the Related Art
An oil artificial lift device is a device that transforms rotary mechanical energy to linear mechanical energy and in turn pumps the oil from underground to ground surface. Presently there are many artificial lift technologies available. They have their advantages as well as shortcomings. Currently available electrical submersible pump uses a rotary motor to rotate a vane wheel, thereby pumping cruel oil to the ground surface. In general, an electrical submersible pump is used on large quantity oil production well. It is easy to manage but its initial investment as well as its electrical consumption is high. Progressive cavity pump requires less initial investment with broader application. However, this progressive cavity pump lasts shorter with higher breakdown rate. The most popular artificial lift today is beam/sucker-rod pumping comprising a motor-driven surface system lilting sucker rods within the tubing string to operate a downhole reciprocating pump. Beam pumping is durable with low breakdown rate, however, it has the drawbacks of complicated structure, low performance, and high electric energy consumption.